The mobile communication system refers to a system in which a service provider provides communication services for a user terminal (such as a mobile phone) by deploying a wireless access network device (such as a base station) and a core network device (such as a Home Location Register (HLR)). The mobile communication has experienced the first generation, the second generation, the third generation, and the fourth generation. The first generation mobile communication refers to the original analog and voice call-only cellular phone standards, and mainly adopts an analog technology and a Frequency Division Multiple Access (FDMA) access method. The second generation mobile communication introduces a digital technology, improves network capacity, improves voice quality and confidentiality, and is represented by “Global System for Mobile Communication (GSM)” and “Code Division Multiple Access (CDMA) IS-95. The third generation mobile communication mainly refers to the CDMA2000 technology, the WCDMA technology and the TD-SCDMA technology, which all use CDMA as an access technology. The fourth generation mobile communication system is relatively and internationally unified in standard and is long term evolution/long term evolution-advanced (LTE/LTE-A) developed by the international organization for standardization 3GPP, the downlink of which is based on the access way of Orthogonal Frequency Division Multiple Access (OFDMA), and the uplink of which is based on the access way of Single Carrier-Frequency Division Multiple Access (SC-FDMA). According to the flexible bandwidth and the self-adaptive modulation and coding manner, the high-speed transmission with a downlink peak rate of 1 Gbps and an uplink peak rate of 500 Mbps is achieved.
MuLTEfire is the LTE technology formed by newly defining an uplink transmission method based on the LTE R13 LAA downlink transmission method, and can independently work in an unlicensed frequency band, that is, stand-alone LTE-U. The MuLTEfire (abbreviated as MF) supports two network modes (or network services), which are an Evolved Packet Core (EPC) connected mode (as shown in FIG. 1) and a Neutral Host (abbreviated as NH) mode. The network architecture is as shown in FIG. 2. The MF network can also support the two network modes at the same time.
For the UE, after accessing the MF network, it is necessary to firstly identify the network mode and obtain the public land mobile network identity (PLMN-ID) and/or the MF network ID and the service provider ID according to the corresponding network mode, while in the conventional LTE network, the operator ID is informed by broadcasting a PLMN-ID List through SIB1.
For the EPC connected mode, the PLMN-ID in the existing LTE is used. The existing PLMN-ID can represent 6 decimal numbers with 24 bits, and every 4 bits correspond to one decimal number. The first 12 bits are used to represent the Mobile Country Code (MCC) of 3 decimal numbers. Te last 12 bits are used to represent the Mobile Network Code (MNC) of the 3 decimal numbers or the first 8 bits of the last 12 bits are used to represent the MNC of 2 decimal numbers, as shown in FIG. 3.
Some new IDs are specifically defined for the NH mode, including: an MF-ID for the MF network identity, a PSP-ID for the service provider identity, and an MFGPLMN-ID for the MF unified identity of the NH mode, which uses the value specially reserved for the MF in PLMN-ID fields. For the MF-ID, the same MF network has only one MF-ID for indicating the network, and the MF-ID contains a globally unique MF-ID and a randomly-selected MF-ID. For the MF network using the randomly-selected MF-ID, the MF-ID can be randomly-selected by the MF network. Therefore, the collision probability that different MF networks select the same MF-ID depends on the selection length of the MF-ID and the number of the MF networks. For the PSP-ID, one MF network can broadcast multiple PSP-IDs for supporting multiple service providers to share the MF network to provide services.
However, on one hand, the UE access network needs to be able to identify the supported network mode according to a network broadcast message. However, since the EPC connected network mode and the NH network mode use the IDs of completely different types and numbers, different formats of the message (such as SIB1 or eSIB or SIBx) are caused, which further results in the increase of protocol complexity.
On the other hand, for the MF network of the NH mode, the use of a shorter randomly-selected MF-ID length will lead to the larger collision probability when the number of the MF networks is larger. As a result, the UE selects the wrong MF network. While if the longer MF-ID is used, a greater system overhead will be caused, and the spectrum efficiency is reduced.
At present, there is no effective solution to the above problems yet.